local voucherId = ARGV[1]
local userId = ARGV[2]

local stockKey = "seckill:stock:" .. voucherId
local orderKey = "seckill:order:" .. voucherId

if(tonumber( redis.call("get", stockKey))<=0)then
    return 1
end
if(redis.call("sismember", orderKey, userId) == 1)then
    return 2
end
redis.call("incrby", stockKey, -1)
redis.call("sadd", orderKey, userId)

return 0